Semiconductor laser device

Abstract

Provided are a lens, a stem, an LD chip to emit laser light with a beam center directed along a mounting surface of the stem, and a PD chip having a reflective surface formed with a dielectric multilayer film on its surface, reflecting the laser light emitted from the LD chip toward the lens, and measuring an amount of the laser light, wherein the LD chip is provided with a waveguide portion having a tip portion that is formed on a side of a front end face and has a width of 0.5 to 0.7 μm, and having a tapered portion that is connected to the tip portion and becomes narrower toward the tip portion at a gradient of 0.018 to 0.033.

1 . A semiconductor laser device, comprising:
 a lens;   a stem disposed so as to be opposed to the lens with a space therebetween;   a semiconductor laser element to emit laser light with a beam center directed along an opposed surface of the stem to the lens; and   a photodiode element having a reflective surface formed with a dielectric multilayer film on its surface, reflecting the laser light emitted from the semiconductor laser element toward the lens, and measuring an amount of the laser light, wherein   the semiconductor laser element is provided with a waveguide portion having a tip portion that is formed at an end portion on an emission side of the laser light and has a width of 0.5 to 0.7 μm, and having a tapered portion that is connected to the tip portion and becomes narrower toward the tip portion at a gradient of 0.018 to 0.033.   
     
     
         2 . The semiconductor laser device according to  claim 1 , wherein the semiconductor laser element emits the laser light at a spread angle of 15° to 25° with respect to the beam center. 
     
     
         3 . The semiconductor laser device according to  claim 2 , wherein the spread angle is 20° to 23°. 
     
     
         4 .- 10 . (canceled) 
     
     
         11 . The semiconductor laser device according to  claim 1 , wherein the semiconductor laser element emits the light such that the beam center thereof is directed toward the opposed surface at an inclination angle α, and the photodiode element is disposed such that the reflective surface is inclined at an angle of 45°−α/2 with respect to the opposed surface. 
     
     
         12 . The semiconductor laser device according to  claim 2 , wherein the semiconductor laser element emits the light such that the beam center thereof is directed toward the opposed surface at an inclination angle α, and the photodiode element is disposed such that the reflective surface is inclined at an angle of 45°−α/2 with respect to the opposed surface. 
     
     
         13 . The semiconductor laser device according to  claim 3 , wherein the semiconductor laser element emits the light such that the beam center thereof is directed toward the opposed surface at an inclination angle α, and the photodiode element is disposed such that the reflective surface is inclined at an angle of 45°−α/2 with respect to the opposed surface. 
     
     
         14 . The semiconductor laser device according to  claim 11 , wherein a front end face of the semiconductor laser element is inclined with respect to a lamination direction of a chip. 
     
     
         15 . The semiconductor laser device according to  claim 12 , wherein a front end face of the semiconductor laser element is inclined with respect to a lamination direction of a chip. 
     
     
         16 . The semiconductor laser device according to  claim 13 , wherein a front end face of the semiconductor laser element is inclined with respect to a lamination direction of a chip. 
     
     
         17 . The semiconductor laser device according to  claim 11 , wherein the semiconductor laser element is disposed such that a lamination direction of a chip is parallel to the opposed surface. 
     
     
         18 . The semiconductor laser device according to  claim 12 , wherein the semiconductor laser element is disposed such that a lamination direction of a chip is parallel to the opposed surface. 
     
     
         19 . The semiconductor laser device according to  claim 13 , wherein the semiconductor laser element is disposed such that a lamination direction of a chip is parallel to the opposed surface. 
     
     
         20 . The semiconductor laser device according to  claim 17 , wherein the waveguide portion of the semiconductor laser element is curved in a plane perpendicular to the lamination direction of the chip. 
     
     
         21 . The semiconductor laser device according to  claim 18 , wherein the waveguide portion of the semiconductor laser element is curved in a plane perpendicular to the lamination direction of the chip. 
     
     
         22 . The semiconductor laser device according to  claim 19 , wherein the waveguide portion of the semiconductor laser element is curved in a plane perpendicular to the lamination direction of the chip. 
     
     
         23 . The semiconductor laser device according to  claim 1 , wherein an end portion of the photodiode element on a side closer to the semiconductor laser element is disposed in an inclined portion that extends to a position of a recess formed from the opposed surface. 
     
     
         24 . The semiconductor laser device according to  claim 11 , wherein an end portion of the photodiode element on a side closer to the semiconductor laser element is disposed in an inclined portion that extends to a position of a recess formed from the opposed surface. 
     
     
         25 . The semiconductor laser device according to  claim 1 , wherein the reflective surface is formed in a concave shape. 
     
     
         26 . The semiconductor laser device according to  claim 11 , wherein the reflective surface is formed in a concave shape. 
     
     
         27 . The semiconductor laser device according to  claim 1 , wherein the waveguide portion is composed of a transparent waveguide.